. >>> correspondent lem tucker from nbc news. the day afr woodstock. brings us to our final story tonight. if you drive from this city north, along a series of rural roads, through farm country, in upstate new york, you would drive right by it if you didn't see the marker. and you would likely never realize you were driving past the site of a gathering that changed a generati of americans. woodstock started 40 years ago n memories or not. have their those who weren't there have seen the images. one in particular telling the story of the time in the upwards of 500,000 people who came together.